138940019 has 2 divisors, whose sum is σ = 138940020. Its totient is φ = 138940018.

The previous prime is 138940013. The next prime is 138940051. The reversal of 138940019 is 910049831.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 138940019 - 2⁴ = 138940003 is a prime.

It is a super-2 number, since 2×138940019² = 38608657759440722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (138940013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69470009 + 69470010.

It is an arithmetic number, because the mean of its divisors is an integer number (69470010).

Almost surely, 2^138940019 is an apocalyptic number.

138940019 is a deficient number, since it is larger than the sum of its proper divisors (1).

138940019 is an equidigital number, since it uses as much as digits as its factorization.

138940019 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 138940019 is about 11787.2820870632. The cubic root of 138940019 is about 517.9356257863.

The spelling of 138940019 in words is "one hundred thirty-eight million, nine hundred forty thousand, nineteen".